Lightly grease inside of Dutch oven. On a lightly floured surface, flatten thawed dough slightly. Cut each loaf into 4 pieces. Form each piece into a rope about 18in long. Brush each rope with melted margarine on all sides. Stir together sugar, brown sugar, and cinnamon. Place mixture on sheet of foil. Roll rope in sugar mixture to coat evenly. Shape rope into a coil in the center of the Dutch oven. Roll another rope in sugar. Attach securely to end of first rope and continue coil. Do the same with remaining ropes. Sprinkle with chopped pecans. Cover and let rise for about 30-40 minutes. Bake at 350 for 30 minutes. Cover with foil last 15 minutes to prevent browning if necessary. Cool about 15 minutes. Stir together powdered sugar, vanilla, and enough milk to make glaze and spoon over cake. Serve